src/kernel/context/ContextBoost.cpp

   1 /* Copyright (c) 2015-2018. The SimGrid Team. All rights reserved.          */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 #include "ContextBoost.hpp"
   7 #include "context_private.hpp"
   8 #include "simgrid/Exception.hpp"
   9 #include "src/simix/smx_private.hpp"
  10
  11 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
  12
  13 namespace simgrid {
  14 namespace kernel {
  15 namespace context {
  16
  17 // BoostContextFactory
  18
  19 BoostContextFactory::BoostContextFactory()
  20     : ContextFactory("BoostContextFactory"), parallel_(SIMIX_context_is_parallel())
  21 {
  22   BoostContext::setMaestro(nullptr);
  23   if (parallel_) {
  24 #if HAVE_THREAD_CONTEXTS
  25     ParallelBoostContext::initialize();
  26 #else
  27     xbt_die("No thread support for parallel context execution");
  28 #endif
  29   }
  30 }
  31
  32 BoostContextFactory::~BoostContextFactory()
  33 {
  34 #if HAVE_THREAD_CONTEXTS
  35   if (parallel_)
  36     ParallelBoostContext::finalize();
  37 #endif
  38 }
  39
  40 smx_context_t BoostContextFactory::create_context(std::function<void()> code, void_pfn_smxprocess_t cleanup_func,
  41                                                   smx_actor_t process)
  42 {
  43 #if HAVE_THREAD_CONTEXTS
  44   if (parallel_)
  45     return this->new_context<ParallelBoostContext>(std::move(code), cleanup_func, process);
  46 #endif
  47
  48   return this->new_context<SerialBoostContext>(std::move(code), cleanup_func, process);
  49 }
  50
  51 void BoostContextFactory::run_all()
  52 {
  53 #if HAVE_THREAD_CONTEXTS
  54   if (parallel_)
  55     ParallelBoostContext::run_all();
  56   else
  57 #endif
  58     SerialBoostContext::run_all();
  59 }
  60
  61 // BoostContext
  62
  63 BoostContext* BoostContext::maestro_context_ = nullptr;
  64
  65 BoostContext::BoostContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
  66     : Context(std::move(code), cleanup_func, process)
  67 {
  68
  69   /* if the user provided a function for the process then use it, otherwise it is the context for maestro */
  70   if (has_code()) {
  71     this->stack_ = SIMIX_context_stack_new();
  72     /* We need to pass the bottom of the stack to make_fcontext,
  73        depending on the stack direction it may be the lower or higher address: */
  74 #if PTH_STACKGROWTH == -1
  75     void* stack = static_cast<char*>(this->stack_) + smx_context_usable_stack_size;
  76 #else
  77     void* stack = this->stack_;
  78 #endif
  79     ASAN_ONLY(this->asan_stack_ = stack);
  80 #if BOOST_VERSION < 106100
  81     this->fc_ = boost::context::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
  82 #else
  83     this->fc_ = boost::context::detail::make_fcontext(stack, smx_context_usable_stack_size, BoostContext::wrapper);
  84 #endif
  85   } else {
  86 #if BOOST_VERSION < 105600
  87     this->fc_ = new boost::context::fcontext_t();
  88 #endif
  89     if (BoostContext::maestro_context_ == nullptr)
  90       BoostContext::maestro_context_ = this;
  91   }
  92 }
  93
  94 BoostContext::~BoostContext()
  95 {
  96 #if BOOST_VERSION < 105600
  97   if (not this->stack_)
  98     delete this->fc_;
  99 #endif
 100   if (this == maestro_context_)
 101     maestro_context_ = nullptr;
 102   SIMIX_context_stack_delete(this->stack_);
 103 }
 104
 105 void BoostContext::wrapper(BoostContext::arg_type arg)
 106 {
 107 #if BOOST_VERSION < 106100
 108   BoostContext* context = reinterpret_cast<BoostContext*>(arg);
 109 #else
 110   BoostContext* context = static_cast<BoostContext**>(arg.data)[1];
 111   ASAN_ONLY(xbt_assert(context->asan_ctx_ == static_cast<BoostContext**>(arg.data)[0]));
 112   ASAN_FINISH_SWITCH(nullptr, &context->asan_ctx_->asan_stack_, &context->asan_ctx_->asan_stack_size_);
 113   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 114 #endif
 115   try {
 116     (*context)();
 117   } catch (StopRequest const&) {
 118     XBT_DEBUG("Caught a StopRequest");
 119   } catch (simgrid::HostFailureException const&) {
 120     XBT_DEBUG("Caught an HostFailureException");
 121   }
 122   context->Context::stop();
 123   ASAN_ONLY(context->asan_stop_ = true);
 124   context->suspend();
 125 }
 126
 127 inline void BoostContext::swap(BoostContext* from, BoostContext* to)
 128 {
 129 #if BOOST_VERSION < 105600
 130   boost::context::jump_fcontext(from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 131 #elif BOOST_VERSION < 106100
 132   boost::context::jump_fcontext(&from->fc_, to->fc_, reinterpret_cast<intptr_t>(to));
 133 #else
 134   BoostContext* ctx[2] = {from, to};
 135   ASAN_ONLY(void* fake_stack = nullptr);
 136   ASAN_ONLY(to->asan_ctx_ = from);
 137   ASAN_START_SWITCH(from->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_);
 138   boost::context::detail::transfer_t arg = boost::context::detail::jump_fcontext(to->fc_, ctx);
 139   ASAN_ONLY(xbt_assert(from->asan_ctx_ == static_cast<BoostContext**>(arg.data)[0]));
 140   ASAN_FINISH_SWITCH(fake_stack, &from->asan_ctx_->asan_stack_, &from->asan_ctx_->asan_stack_size_);
 141   static_cast<BoostContext**>(arg.data)[0]->fc_ = arg.fctx;
 142 #endif
 143 }
 144
 145 void BoostContext::stop()
 146 {
 147   Context::stop();
 148   throw StopRequest();
 149 }
 150
 151 // SerialBoostContext
 152
 153 unsigned long SerialBoostContext::process_index_;
 154
 155 void SerialBoostContext::suspend()
 156 {
 157   /* determine the next context */
 158   SerialBoostContext* next_context;
 159   unsigned long int i = process_index_;
 160   process_index_++;
 161
 162   if (i < simix_global->process_to_run.size()) {
 163     /* execute the next process */
 164     XBT_DEBUG("Run next process");
 165     next_context = static_cast<SerialBoostContext*>(simix_global->process_to_run[i]->context_);
 166   } else {
 167     /* all processes were run, return to maestro */
 168     XBT_DEBUG("No more process to run");
 169     next_context = static_cast<SerialBoostContext*>(BoostContext::getMaestro());
 170   }
 171   SIMIX_context_set_current(next_context);
 172   BoostContext::swap(this, next_context);
 173 }
 174
 175 void SerialBoostContext::resume()
 176 {
 177   SIMIX_context_set_current(this);
 178   BoostContext::swap(BoostContext::getMaestro(), this);
 179 }
 180
 181 void SerialBoostContext::run_all()
 182 {
 183   if (simix_global->process_to_run.empty())
 184     return;
 185   smx_actor_t first_process = simix_global->process_to_run.front();
 186   process_index_            = 1;
 187   /* execute the first process */
 188   static_cast<SerialBoostContext*>(first_process->context_)->resume();
 189 }
 190
 191 // ParallelBoostContext
 192
 193 #if HAVE_THREAD_CONTEXTS
 194
 195 simgrid::xbt::Parmap<smx_actor_t>* ParallelBoostContext::parmap_;
 196 std::atomic<uintptr_t> ParallelBoostContext::threads_working_;
 197 thread_local uintptr_t ParallelBoostContext::worker_id_;
 198 std::vector<ParallelBoostContext*> ParallelBoostContext::workers_context_;
 199
 200 void ParallelBoostContext::initialize()
 201 {
 202   parmap_ = nullptr;
 203   workers_context_.clear();
 204   workers_context_.resize(SIMIX_context_get_nthreads(), nullptr);
 205 }
 206
 207 void ParallelBoostContext::finalize()
 208 {
 209   delete parmap_;
 210   parmap_ = nullptr;
 211   workers_context_.clear();
 212 }
 213
 214 void ParallelBoostContext::run_all()
 215 {
 216   threads_working_ = 0;
 217   if (parmap_ == nullptr)
 218     parmap_ = new simgrid::xbt::Parmap<smx_actor_t>(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode());
 219   parmap_->apply(
 220       [](smx_actor_t process) {
 221         ParallelBoostContext* context = static_cast<ParallelBoostContext*>(process->context_);
 222         context->resume();
 223       },
 224       simix_global->process_to_run);
 225 }
 226
 227 void ParallelBoostContext::suspend()
 228 {
 229   boost::optional<smx_actor_t> next_work = parmap_->next();
 230   ParallelBoostContext* next_context;
 231   if (next_work) {
 232     XBT_DEBUG("Run next process");
 233     next_context = static_cast<ParallelBoostContext*>(next_work.get()->context_);
 234   } else {
 235     XBT_DEBUG("No more processes to run");
 236     next_context = workers_context_[worker_id_];
 237   }
 238
 239   SIMIX_context_set_current(next_context);
 240   BoostContext::swap(this, next_context);
 241 }
 242
 243 void ParallelBoostContext::resume()
 244 {
 245   worker_id_ = threads_working_.fetch_add(1, std::memory_order_relaxed);
 246
 247   ParallelBoostContext* worker_context = static_cast<ParallelBoostContext*>(SIMIX_context_self());
 248   workers_context_[worker_id_]         = worker_context;
 249
 250   SIMIX_context_set_current(this);
 251   BoostContext::swap(worker_context, this);
 252 }
 253
 254 #endif
 255
 256 XBT_PRIVATE ContextFactory* boost_factory()
 257 {
 258   XBT_VERB("Using Boost contexts. Welcome to the 21th century.");
 259   return new BoostContextFactory();
 260 }
 261 }}} // namespace